Control of electric apparatus



pt. 13, 1927. M BUCHHOLZ 1,642,400

CONTROL OF ELECTRIC APPARATUS Original Filed Sept. 15, 1922 /n van for:

ax BuC/Y/w/Z iffy Patented Sept. 13, 1927.

arent MAX BUCH HOLZ, OF GASSEL, GERMANY.

CONTROL OF ELECTRIC APPARATUS.

Original application filed September 15, 1922, Serial N9. 588,457, and in Germany- January 21, 1922. I

- Divided and this application filed April 16, 1925.

My invention has reference to a method and means for protecting electric apparatus operating in an insulating liquid, such as oil transformers, oil switches, grounding throttling coils, resistances and the like, and

it isone of the important objectsof my in-' bubbles of gases of decomposition are formed which can operate a protective means, for instance an electric contact, either a working or .a closed contact, which is adapted to switch out of circuit the'apparatus to be protected, or which will operate an alarm or an nunciator device indicatin the disturbance, or which is adapted to e ect both kinds of operations. The gases formed by decomposition may influence the protective means in different ways, this application being a division of my copending application Serial Number 588,457 filed September 15, 1922.

I may for instance utilize a displacement of the insulating liquid occurring in consequence ofthe unnormal conditions 'of working mentioned above to vary the operative conditions of the protective circult.

A protective device embodying this invention isillustrated in the drawings annexed to this specification by way of example in a purely diagrammatic manner.

The drawing shows the elevation of an o1l insulated transformer with an overflow pipe for the oil and a balance beam acting as a switch for the opening and closing of the protective circuit.

In the drawing a is a transformer casing, I) is the core of the transformer, c are the windings, d are the leading-in insulations for the conductors e is an oil switch wlth a 7 releasing coil 7' and g 15 a source of current safety dewhich, upon the operation of the vice,'excites the coil, opens the 011 switch and causes the switching-out of the apparatus. 50 o is an overflow pipe mounted in the cover Serial No. 23,675

of the vessel a and n is an expansion vessel in communication with this pipe. 4) is a cup disposed below the upper end of the overflow at one end of a balance beam u pivoted on an axle w and having a contact piece is attached to its other end, The protective circuit comprising the source of current 9 and the coil 7 is connected with the axle w and can be closed or opened by the contact piece it. The core a of the coil is influenced by a coil spring m and serves to retain a short circuiting device 3 in inoperative position. The dev ce 3 on being allowed to drop, will establish a short circuit whereby the fuses t,

t will be destroyed and thereby cut out the transformer. Any gases of decomposition formed in the vessel a'will cause oil to be expelled through the overflow tube 0, thereby ejecting small quantities of oil from the free end of the tube. The ejected oil, in droppinginto the cup 1), will b its. weight cause the contact is to be opene whereupon the core 2 will be withdrawn by the spring :17, thereby releasing the short circuiting de- Vice 3 and thus cutting out thetransformer.

The circuit to be controlled by the contacts referred to may excite either directly or by the medium of an intermediate relay the releasing coil of an oil switch which interrupts the endangered circuit. In the case of apparatus the clrcuit of which does not include an oil switch, as frequently occurs, for instance in the cases of transformers mounted in the field at wide distances apart, other provisions should be made for thepurposes of this invention.

Besides the form of construction herein shown and described, the invention is susceptible of a variety of other modifications and forms of application of the princi le of my invention all of which operates su stantially in a similar manner. The means of connecting the'contacting device with the releasing circuit and the switching means are open to changes and alterations without any material importance for the operation of the apparatus according to my invention which in its broad aspects comprises the operation of safety devices for electric apparatus or the like, adapted for operation by vapors, fumes, gases or similar emanatlons liberated and expelled from the insulating medium, and means adapted to be operatively influenced'by such emanations, and connected to fuses or equivalent safety means, the instrumentalities shown and described in this specification as embodiments of these principles being susceptible of modifications without deviating from the spirit of my invention as set forth in the claims.

In the claims the term gases is meant to comprise also vapors and fumes.

I claim 1. The method of controlling unnormal working conditions of liquid-insulated electric apparatus, comprising causing an expulsion of insulating liquid occurring in consequence of such a decomposition of such liquid and causing such expulsion to vary the operative conditions of a protective circuit.

2. Protective system for liquid-insulated electric apparatus comprising a container and a supplyof insulating liquid surrounding the apparatus to be protected, a protective circuit and means adapted to be operated by an expulsion of insulating liquid occurring in consequence of a decomposition of such llquid for varying the operative conditions of said circuit.

3.,Protective system for liquid-insulated electric apparatus comprising a closed container for said apparatus, a supply of insulating liquid in said container surroundingsaid apparatus and adapted to completely fill said container, a protective circuit, an overflow tube on said container and a contact device operatively related to said tube and adapted to be actuated by insulating liquid escaping from said tube.

4. Protective system for liquid-insulated electric apparatus comprising a closed container for said apparatus, a supply of insulating liquid in said container surrounding said apparatus and adapted to completely fill said container, a protective circuit, an overflow tube on said container, 9. double armed'contact lever and a cup on said lever below the free end of saidoverflow tube and adapted to be actuated by insulating liquid escaping from said tube.

5. Protective system for liquid insulated electric ap aratus comprising a container and a supp y of insulat ng liquid surrounding the apparatus to be protected, a protective means adapted to be operated by an expulsion of insulating liquid occurring in consequence of a. decomposition of such liquid for varying the operative conditions of said protective means.

In testimony whereof I afiix my signature.

MAX BUCHHOLZ. 

